Gas prices may be on the rise following the U.S. airstrike in Syria. Oil prices hit a one-month high on Friday after the United States fired missiles at a Syrian government airbase, sending shockwaves through global markets and raising concerns that the conflict could spread in the oil-rich region. As of Friday morning, the average per-gallon price for gasoline was $2.39, or an increase of about one penny from Thursday, according to gas tracking site GasBuddy.